The purpose of this Workshop is to stimulate the use of quantitative multidisciplinary methods for studying the progression and regression of atherosclerotic lesions by critically reviewing the current state of knowledge about these methods, and by recommending goals for their future research and development. Further, this workshop seeks to promote interaction among investigators from several disciplines with the objectives of integrating and exploiting traditional and more recently developed techniques that are used in atherosclerosis evaluation. A panel of 25 speakers and 15 discussants, representing considerable expertise in radiology, ultrasonography, pathology and biochemistry will define the current state of knowledge of new methods in atherosclerosis evaluation and will develop criteria for further validation and correlation studies. To disseminate the information and recommendations of the Workshop, the Organizing Committee will prepare and publish a comprehensive review of these topics utilizing extended abstracts and discussions prepared by the invited speakers. Abstracts of invited presentations will be distributed to all speakers and discussants prior to the Workshop. This Workshop was designed and organized by the Committee on Coronary Lesions and Myocardial Infarctions of the Council on Arteriosclerosis (American Heart Association), and reflects the objective of this Committee in the evaluation of arteriosclerotic lesions. The Organizing Committee has sought and acquired financial support for this Workshop from the American Heart Association.